Artificial leg



UNITE STATES' N union.

W C. STONE, OF BOSTON, MASSACHUSETTS.

ARTIFICIAL LEG.

Specification of Letters Patent No. 7,847, dated December 17, 1850.

T 0 all whom t may 0011.061111.:

Be it known lthat I, IV. C. STONE, of Boston, in'county of Suffolk and State of Massachusetts, have invented a new and useful Improvement in Artificial Legs to Prevent the Knee-Joint F rom Turning or Slipping Outin lalking; and I do hereby declare that the following is a full and exact descript-ion thereof.

The nature of my invention consists in providing a stop in the knee-joint of the artiicial leg to prevent the revolution of the joint until the step is taken, as in the case of other legs there is nothing to prevent the outslip of the joint, and consequently a fall.

To enable others skilled in the art to make and use my invention I will proceed to describe its construction and operat-ion.

I construct my artificial leg after the usual forms, the leg being hollowed out. I put my hinges on each side (as seen in the drawing Section l) of the knee joint. the center of' which hinges to revolve below the joint, I then drill holes A one inch above the center of the hinges. I on the inside of the leg rivet two springs (Sec. 2 b b) with pins attached (c c) to play into the holes (A A) in the hinges, which prevents the revolution of the hinge. I then put a revolving lever (D) between the springs Z), b, which plays against the springs. I then attach a rod (E) to the lever (D) which I pass down to the ankle, there I make a hinge in the rod at to Work with the ankle joint, then the rod is continued down to the bottom ot' the heel (see g) and projects of an inch. Then `I put o-n the bottom ot the heel a spring (I-I Sec. l) which I fasten in 'the hollow of the foot, (at I) which plays against the rod that projects out from the bottom of the heel. Thus then by placing the foot on the ground causing a pressure o-n the spring H on the bottom of the heel, forcing the rod E up t-he leg causes the lever to revolve against the springs b b, to which are the pins c, c, attached, causing the pins to be pressed into the holes A in the hinges, thereby preventing the action of the hinges also securing the knee`joint from turning, slipping or revolving out while a person would be in the act of stepping, while the pins are in he is sure, and fear is removed.

)Vhat I claim as my invention and desire to secure by Letters Patent, is-F The application of the whole action from the heel up to the knee joint in the artificial leg, which action prevents the knee joint from turning, slipping or revolving out in the act of stepping as herein described, using for that purpose the aforesaid springs rod, lever and pins, or any other substantially the same and which will produce the intended effect.

IV. C. STONE. lVitnesses:

WM. S. GOODRIDGE, A. R. C. PIKE. 

